Polyester fiberfill is used commercially in many end-uses, including pillows and cushions, because of its economic value and desirable aesthetic and nonallergenic properties. Hereinafter the term pillow is often used generically to cover cushions. Most commercial polyester has been in the form of crimped polyester staple fiber of denier about 5-6.
Generally, heretofore, in the manufacture of pillows and cushions, a rolled batt of fluffy unbonded polyester fiberfill has been stuffed into a cover (often referred to as ticking), as disclosed in LeVan U.S. Pat. No. 3,510,888. The pillow or cushion is then forcibly manipulated to redistribute the polyester fiberfill into the shape desired. It has not been customary to bond polyester fiberfill for use in pillows except that a light coating of resin is sometimes used to assist in handling batts and to prevent fiber from sticking through the ticking.
It has generally been considered desirable to maximize the bulk of the polyester fiberfill used in pillows to increase the softness and fluffability. One prior suggestion for improving bulk has been the use of hollow polyester fiberfill, e.g., as disclosed in British Patent No. 1,168,759 and Tolliver U.S. Pat. No. 3,772,137. Another prior suggestion for improving bulk and bulk stability has been to provide the polyester fiberfill with a coating of durable (e.g., wash-resistant) silicone slickener (cured polysiloxane), e.g., as disclosed in Hofmann U.S. Pat. No. 3,271,189 and Mead et al. U.S. Pat. No. 3,454,422.
Pillows filled with polyester fiberfill do not generally have such high resilience as polyurethane foam-filled pillows, but generally have superior softness and down-like aesthetics. It would be desirable to increase the resilience of the polyester fiberfill, when in the pillow, without losing its desirable down-like aesthetics.
Research Disclosure Journal (September 1975) Article No. 13717, page 14, discloses the inclusion in polyester fiberfill of a specific low melting point binder fiber, poly(ethylene terephthalate/isophthalate), and its bonding to improve the stability and handling characteristics of the fiberfill, e.g., in batts, including batts to which polysiloxane slickeners have been applied. Mixtures of polyester fiberfill with lower melting binder fiber are also suggested elsewhere, e.g., in Scott U.S. Pat. No. 4,129,675, which discloses forming a web having a central band made from silicone-slickened polyester hollow fiberfill and outer bands made from a blend of unslickened hollow polyester fiberfill and binder fiber, and forming a batt having a center layer of such silicone-slickened polyester fiberfill and upper and bottom layers of said blend. Stanistreet U.S. Pat. No. 4,068,036 suggests the use of conjugate or bicomponent fibers for use as binder fibers in fiberfill blends.